From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A0A54379C38; Sat, 12 Sep 2026 10:07:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789207642; cv=none; b=OquBvhEYa1x3+thK1j9ivI/aDPVuhJmceHqKC6TEbc1qic4xtunVhLaWtS0XIXu4ubdaFkFz1v9/QqgoH1fk0E+fTCjAKdlx1pGNXvYbwGIuOFFqABF05NiAi1G+9dW0+shgynj0r6cPTG0YEOc53ZpwPuFN1ikHSpMFVssYqSw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789207642; c=relaxed/simple; bh=JKqT6IPAzqX5KS0cZ3KyS6aSRE83N65bJ5HYnTLZJPU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=BnQpilu/DzSkfPGt+lkus8Pqt8AS5rV6spC9V7FaqvDCFQ5E1JUvTpm+8TQmYrhifkqwathTgmtgTeUTr5bjieUvMgpK1xivMHwcS9cTun678YhPNuBZdKyRxi93Pb9PDh4aHdWdtKt+2o07a4iv2p48cKFD48cuycXH7ut4ioA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=p/s4I5YN; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="p/s4I5YN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 932291F000FF; Sat, 12 Sep 2026 10:07:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789207641; bh=tibelXgP3kn6xRKfQXziOAk3+/+rMIlvECoVm50tVDU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=p/s4I5YNIana+HIvpsD+ncLa6MiyJ6WconlyURj1jLpwegaWaCqdSLRQQWsGfjMw8 EBUxPPyGSY3+NmB/CEF+AEbb1kCHctzmVnGD6fisUXqeX/+5cpI1CyELmcuPLLs9eW fCQnXMPF5Y5bdzlqDVtrsW/0ulg9HNGczMJL8ao8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gui-Dong Han , Sasha Levin Subject: [PATCH 6.18 0452/1518] misc: bcm-vk: Use acquire/release for msgq_inited Date: Sat, 12 Sep 2026 08:43:41 +0200 Message-ID: <20260912065633.674135983@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065623.398859879@linuxfoundation.org> References: <20260912065623.398859879@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gui-Dong Han [ Upstream commit 61b101c6a150057b6d512421ed108aed16e822ea ] bcm_vk_sync_msgq() fills the message queue information and then sets msgq_inited. Readers call bcm_vk_drv_access_ok() before accessing the message queues and their cached queue information. atomic_set()/atomic_read() do not order those accesses. A reader can see msgq_inited set while still seeing stale queue information. Use release when publishing the initialized queues and acquire when checking the gate. Keep the clear in bcm_vk_blk_drv_access() as atomic_set(). It closes the gate and does not publish queue state to readers. Fixes: 111d746bb476 ("misc: bcm-vk: add VK messaging support") Signed-off-by: Gui-Dong Han Link: https://patch.msgid.link/20260603021127.3285057-1-hanguidong02@gmail.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/misc/bcm-vk/bcm_vk_msg.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.c b/drivers/misc/bcm-vk/bcm_vk_msg.c index 665a3888708ac..a36a6c7d384a9 100644 --- a/drivers/misc/bcm-vk/bcm_vk_msg.c +++ b/drivers/misc/bcm-vk/bcm_vk_msg.c @@ -108,7 +108,8 @@ u32 msgq_avail_space(const struct bcm_vk_msgq __iomem *msgq, bool bcm_vk_drv_access_ok(struct bcm_vk *vk) { - return (!!atomic_read(&vk->msgq_inited)); + /* Pair with the release store after message queue initialization. */ + return !!atomic_read_acquire(&vk->msgq_inited); } void bcm_vk_set_host_alert(struct bcm_vk *vk, u32 bit_mask) @@ -501,7 +502,8 @@ int bcm_vk_sync_msgq(struct bcm_vk *vk, bool force_sync) msgq++; } } - atomic_set(&vk->msgq_inited, 1); + /* Publish message queue info before allowing driver access. */ + atomic_set_release(&vk->msgq_inited, 1); return ret; } -- 2.53.0